1. Field of the Invention
This invention is related to the provision of calling line identification services to subscribers within a telecommunication network. More specifically, the invention relates to providing such services in an enhanced way using text-to-speech based audio.
2. Description of the Problem
The public switched telephone network (PSTN) increasingly uses a data network called the advanced intelligent network (AIN) that operates in parallel with the voice network-to provide many new, intelligent services such as voicemail, automated callback, and other custom calling features. The standard AIN uses a messaging protocol called signaling system 7 (SS7) to exchange call information between switches. SS7 is based on a set of international standards for high-speed digital communications and serves as the foundation for telephony infrastructures worldwide. In SS7, call control messages are handled by a part of the protocol called Integrated Services Digital Network (ISDN) User Part (ISUP), and queries and responses for databases are handled by a part of the protocol called the Transaction Capability Application Part (TCAP). The SS7 standards are well-known. For further information see Telcordia Technologies, GR-82-CORE, Signaling Transfer Point (STP), December, 1999, and GR-246-CORE, Specification of Signaling System Number 7, December, 1999, both of which are incorporated herein be reference.
One of the most desirable and widely used features provided using AIN services is that of calling line identification, or xe2x80x9ccaller-ID.xe2x80x9d With caller-ID, the number, and possibly the name, of a calling party is retrieved from a database in the SS7 network, coded as digital pulse trains, transmitted to the terminating switch or switching system, and sent to the called subscriber""s telephone set for display on a screen in conjunction with an alerting signal such as a ring. By xe2x80x9cin conjunction withxe2x80x9d we mean just before, during or just after, or, as on most analog phone lines, in between rings. Preferred methods and protocols used for realizing the caller-ID feature on xe2x80x9cplain old telephone systemxe2x80x9d (POTS) phones are discussed in the Telcordia (formerly Bellcore) standards, TR-TSY-000030, xe2x80x9cSPCS Customer Premises Equipment Data Interface,xe2x80x9d November, 1988, and TR-TSY-000031, xe2x80x9cCLASS Feature: Calling Number Delivery,xe2x80x9d June, 1988, which are incorporated herein by reference. With other types of telephone systems, caller-ID information is transmitted as part of the digital signaling between the switch and the phone. These include integrated services digital network (ISDN) and other digital phones, as well as analog display services interface (ADSI) analog phones. Requirements for ADSI data transmission in both the on-hook and off-hook states are specified in Telcordia standard GR-30-CORE, xe2x80x9cVoiceband Data Transmission Interface Generic Requirements,xe2x80x9d December 1994, which is incorporated herein by reference. A problem with caller-ID as defined by these standards is that the subscriber must be able to view the display screen built into or attached to his or her telephone set in order to make use of the information.
Another calling feature made possible by the modern AIN is call waiting. Call waiting and caller-ID service have been combined in a feature called xe2x80x9cSpontaneous Caller Identification with Call-Waiting.xe2x80x9d U.S. Pat. No. 5,263,084 describes this feature, provides background information on both call-waiting and caller-ID, and is incorporated herein by reference. Initially with Spontaneous Caller Identification with Call Waiting, the caller information was provided on a display screen in way a similar to how the information was provided with traditional caller-ID. Recently, however, the service has been offered with audio caller identification. To provide audio caller identification with call waiting, the calling line identification data retrieved over the AIN is sent to a text-to-speech translation system to be translated into audio. The translation system typically resides in an intelligent peripheral (IP) or service node on the AIN. When the feature is active, the called party can hear the number or other information about the calling party in audio format. This audio caller identification requires that the called party be on the phone engaged in a call; it cannot be provided when the subscriber telephone is in an xe2x80x9con-hookxe2x80x9d condition, or before any call is connected.
Currently, the only known way to provide audio caller-ID information to a subscriber when the subscriber customer premises equipment (CPE) is in an on-hook condition is to place text-to-speech translation apparatus at the subscriber CPE. U.S. Pat. No. 6,038,443 describes such a system and is incorporated herein by reference. In this system, an electronic device is connected to the phone line and resides with the CPE. The system intercepts the standard digital pulse train containing the caller-ID information, and provides a rudimentary conversion to digitized speech, so that caller-ID information is spoken while the telephone is ringing. The text-to-speech conversion is provided through simple digit and location information look-up. Optionally, a spoken name can be read if the user has stored this in memory within the device. This system has the disadvantage of requiring the subscriber to purchase extra equipment. Additionally, the crude text-to-speech capability of this device prevents it from ever identifying callers by name unless the user has pre-recorded the name of the caller.
There is a need for a way to provide audible caller-ID using network resources in such a way that the information can be provided to the subscriber when the phone is in an on-hook condition, that is, when the phone is ringing or otherwise processing an incoming call alert. By using network resources to provide the service, the necessity for the subscriber to purchase specialized equipment is eliminated. Ideally, the text-to-speech translation capability that is used should be sophisticated enough to identify callers by name, at least in some circumstances.
The present invention meets the above needs by providing an audible calling line identification system which uses network resources to provide text-to-speech translation services, and audible calling line identification services. With the present invention, these audible calling line identification services are provided to a telephone which is initially in an on-hook state. A subscriber to the service of the invention need not purchase additional equipment; the hardware needed to provide the service is owned and operated by the service provider. In the case of a POTS telephone line, the caller identification information is provided as soon as a subscriber responds to an alerting signal, such as a ring. In the case of other types of phone systems that provide for signaling to be received while an alerting signal is being processed, the audible calling line identification is provided without any subscriber action.
In one embodiment of the invention, a normal alerting signal is sent to the subscriber customer premises equipment (CPE) in response to a call being placed from a caller to the subscriber, using the public switch telephone network (PSTN). At this point, the subscriber CPE is in an on-hook condition. When the subscriber answers the phone, the resulting off-hook condition is detected. Calling line identification (caller ID) data is obtained over the advanced intelligent network (AIN) in the normal fashion. However, instead of sending this data directly to the subscriber CPE, it is first sent to a text-to-speech translation system residing within the network. Once the calling line identification data has been translated into speech, the switching system which serves the subscriber connects the subscriber CPE to the text-to-speech translation system for a period of time long enough for the audio calling line identification to be played to the subscriber. The subscriber is then given the opportunity to supply a subscriber response to the audio calling line identification, usually by hitting a key on a telephone touch tone pad. The call is then processed in accordance with the subscriber response.
The call processing described above can include many optional steps. The call processing can include, for example, connecting the subscriber and the caller if the subscriber response indicates acceptance of the call. The call processing can also include notifying the caller if the subscriber response indicates non-acceptance of the call. Additionally, in the preferred embodiment, if there is no subscriber response within a specific time period, a default call disposition is executed so that the caller is not left waiting.
If the invention is implemented in a telephone system which provides for on-hook signaling between the switch and the subscriber CPE, it is not necessary for the subscriber to answer the phone to receive the audible calling line identification of the invention. In this case the switch serving the subscriber CPE directs the subscriber CPE to activate a speaker when a call is placed to the subscriber CPE. The switch obtains calling line identification data as before, and sends the calling line identification data to the text-to-speech translation system. When the text-to-speech translation is complete, the switch connects the text-to-speech translation system to the subscriber CPE so that the audio calling line identification is played at the subscriber CPE over a speaker. In order to implement this embodiment of the invention, the subscriber""s CPE must be able to understand the messaging which is received from the switching system that directs the subscriber CPE to activate a built-in speaker. One way to implement this embodiment is by making use of an analog display services interface (ADSI) telephone system and including the appropriate information in a set-up message which is sent from the switching system to the subscriber CPE. Whether the subscriber CPE actually goes off-hook and connects to the telephone network to receive standard audio in order to play the audible calling line identification, or stays on-hook and receives the audio as part of the on-hook messaging depends on the type of phone system in which the invention is being implemented.
In the specific embodiments discussed, a switching system, or telephone switch, is used to manage the connections and connect the subscriber CPE to the text-to-speech translation system. Such a switching system is operated by computer program code that is stored on a media or delivered to the switching system over a network. A switch which implements the invention includes a switching matrix, one or more peripheral modules connected to the switching matrix, one or more input/output devices connected to the switching matrix, and a computing module which controls the operation of the switch in accordance with a computer program.
If the invention is implemented using a xe2x80x9csmartxe2x80x9d subscriber device such as a telephone with signaling capability, appropriate computer program code is also stored within the subscriber device. This computer code allows the device to recognize the commands necessary to implement the invention. Preferably, this computer code will operate the device in accordance with agreed standards, except for the improvement necessary to implement the present invention. In the case of digital phones, such as ISDN or Internet protocol phones, the alerting signal at the phone is triggered by an alerting message. The subscriber device typically includes a control block which has a microcontroller or microprocessor and supporting circuitry and the memory required to store the computer program code. Such a device also includes a network interface, and an input/output block which provides a keypad interface and possibly a display screen. A speaker and handset is normally included. In the case of an analog phone, the speaker and handset are connected to the rest of the hardware through an amplifier and/or a switching arrangement. In the case of a digital telephone, the speaker and handset are connected to an encoder/decoder, also known as a CODEC. The hardware and computer program code within the switching system, and the hardware and computer program code within the subscriber CPE, if any, are the means for implementing the present invention.